Food poisoning

Information and advice

The following advice and precautions could help prevent food poisoning being passed onto other people, and it could help prevent you and your family suffering from food poisoning in the future.

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Food poisoning

Food poisoning is an illness, usually caused by eating or drinking food or water contaminated by bacteria (germs) or the poisons that they produce. It can be caught from food eaten at home, at restaurants, or abroad.

The common symptoms associated with food poisoning include:-

  • diarrhoea
  • vomiting
  • nausea and
  • stomach cramps.

These usually occur within two to thirty-six hours of consumption of the food, although with some types of food poisoning, illness may not occur for days or even weeks.

The last thing eaten is not necessarily the cause of the food poisoning.

The symptoms usually last between one and seven days, although this may be longer.

All the time you have the symptoms, and in some cases for some time after, you can transmit the infection to other people if you are not careful.

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How you catch food poisoning

Food poisoning is mainly caught from contaminated food.

The common causes of food poisoning are:

  • under cooked meat or poultry
  • inadequate temperature control of food
  • food contaminated by raw meat or poultry
  • food contaminated by food handlers with unclean hands
  • food contaminated by unclean equipment

Incorrect storage, handling, preparation and cooking of food can lead to food poisoning, in your own home as well as in food businesses. Unfortunately, contaminated food usually looks, smells and tastes fine, so you cannot tell that it is contaminated.

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The role of Environmental Health

Doctors have to notify the Environmental Health Service about cases of certain infectious diseases, including food poisoning, and the Environmental Health Service has a duty to investigate such cases.

We try to establish the cause of the food poisoning, and we follow this up where necessary by inspecting food premises to help prevent other people suffering from food poisoning.

We also provide advice on precautions which should be taken, especially to people in groups where there is a high risk of passing on the infection. This includes food handlers, young children and people who look after the very young, the elderly or the ill.

Even when the symptoms have cleared, you may still carry and excrete the bacteria for several weeks. Close contacts may also carry and excrete the bacteria, even through they have had no symptoms.

With some types of food poisoning, people in the high risk groups mentioned above who are carrying the bacteria, must not return to work until they have been cleared by ourselves.

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What to do whilst you or a member of your family have food poisoning

Take care with your hygiene, and in particular, wash your hands thoroughly:

  • after using the toilet
  • before handling food and
  • before eating or feeding others.

If you are a food handler, healthcare worker or work with the elderly or children under five years old, do not return to work until you have checked with us.

Food handlers suffering from food poisoning must report this matter to the Environmental Health Service or their employer, by law.

If you are not included in the above list of people, generally you can return to work when your symptoms have cleared, unless the Environmental Health Service or your doctor tell you not to.

Children should return to school 24 hours after the first normal stool, and nursery when their symptoms have cleared for 48 hours.

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General precautions to prevent food poisoning

Personal hygiene

  • Wash hands thoroughly: before and after handling food, especially after handling raw meat and poultry; after using the toilet; after changing nappies and handling soiled clothing; after touching animals, especially before handling food.
  • Cover open cuts and sores which may come into contact with food with waterproof plasters.
  • If possible, do not prepare food for other people when suffering from food poisoning symptoms.

General hygiene

  • Maintain high standards of hygiene in the kitchen. Keep kitchen surfaces and equipment clean and use anti-bacterial cleaning materials where possible.
  • Keep cooked foods and uncooked foods, especially raw meat and poultry, separate. This will also include using separate chopping boards, plates and knives.
  • Keep pets out of the kitchen when preparing food, and keep them off work surfaces.
  • Use pasteurised or UHT milk and cream.
  • When travelling abroad, check before hand that water and ice is safe to consume. If it is not, or if in doubt, make sure it is sterilised using chlorine tablets for example, or buy bottled water.
  • Additionally, avoid eating salads and raw fruit / vegetables that have been washed with non-sterilised water in countries where the water is not safe to consume.
  • If you are sick, elderly, pregnant or susceptible to infections, or are preparing food for such people, toddlers or babies: avoid raw / undercooked eggs; avoid soft cheeses; reheat cook-chill meals until piping hot.

Temperature control

  • Keep all perishable foods in a refrigerator.
  • Your fridge should operate at below 5C to prevent bacteria growing.
  • Store cooked or ready-to-eat foods above raw meat and vegetables.
  • Ensure frozen foods, especially meat and poultry, are fully thawed before cooking.
  • Ensure food is cooked thoroughly.
  • Cool food quickly and refrigerate as soon as possible after cooking.
  • If reheating food ensure that it is piping hot.

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Bacteria and symptom chart

Salmonella

Source Poultry, meat, raw egg products, human and animal excreta, carriers
Vehicle Utensils, work surfaces, hands
Route Raw to cooked / ready-to-eat food
Symptoms Diarrhoea
Onset Period 6-36 hours. Usually 12-24 hours
Recovery 1-7 days

Staphylococcus Toxin

Source Skin, nose, spots and boils
Vehicle Hands, coughs, sneezes, open infected wounds
Route Cooked / ready-to-eat food
Symptoms Vomiting, diarrhoea, pain, cramps
Onset Period 2-6 hours
Recovery Rapid

Campylobacter

Source Animals (especially dogs), poultry, dairy products
Vehicle Hands, undercooked poultry, pork and eggs
Route Undercooked foods, faecal-oral route
Symptoms Abdominal cramp, diarrhoea, often bile stained
Onset Period 2-11 days
Recovery 3 days - 3 weeks

Bacillus Cereus

Source Cereals, environment
Vehicle Surfaces, hands, utensils
Route Cooked rice, corn flour, sauces
Symptoms Acute vomiting, some diarrhoea
Onset period 1-16 hours
Recovery 12-48 hours

Clostridium Perfringens

Source Animal excreta, human excreta, raw meats, dehydrated products
Vehicle Soil, dust, utensils, work surfaces, hands, unwashed vegetables and fruit
Route Warm storage, slow cooking, braised, stewed and steamed foods

Symptoms

 Abdominal pain, diarrhoea
Onset Period 8-22 hours
Recovery 12-48 hours

Clostridium Botulinium

Source Soil, meat, fish, including smoked
Vehicle Imperfectly processed canned and bottled foods
Route Canned and bottled foods
Symptoms Fatigue, dizziness, headache, possible death
Onset Period 24-96 hours
Recovery Very slow, can be fatal

E Coli

Source Human excreta, water
Vehicle Hands, utensils, surfaces
Route Raw foods to cooked / ready-to-eat
Symptoms Diarrhoea (mucus and blood)
Onset Period 12-72 hours
Recovery 1-5 days

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Fact sheets